An image intensifier intensifies (or amplifies) an image having a low level of ambient light (e.g., ambient lighting in a nighttime environment) to a level sufficient for detection of persons and objects by the human eye. Each image intensifier typically includes a photocathode, an electron multiplier such as a microchannel plate, and a phosphor screen. Typically, a first voltage differential between the photocathode and the microchannel plate creates a first electric field in the vacuum between the photocathode and the microchannel plate. A second voltage differential is maintained across the microchannel plate (i.e., the inlet side of the microchannel plate is at a different voltage than the outlet side of the microchannel plate). A third voltage differential between the microchannel plate and the phosphor screen creates a third electric field in the vacuum between the microchannel plate and the phosphor screen.
Enhanced vision systems that include an image intensifier operate by collecting or capturing existing light photons using a simple or compound objective lens array converting the captured photons to photo-electrons using a photocathode, multiplying the photo-electrons to provide a large number of electrons, and creating an image on a phosphor screen. The source of the existing photons may be naturally occurring (e.g., starlight, moonlight) or artificially generated (e.g., street lights, defined wavelength illuminators).
Although the following Detailed Description will proceed with reference being made to illustrative embodiments, many alternatives, modifications and variations thereof will be apparent to those skilled in the art.